A jury yesterday began deliberating the case of a Nassau County jail supervisor, Cpl. Joseph Bergen, who was charged with falsely reporting that an inmate, Thomas Pizzuto, 38, died after slipping in the shower, when he had actually been beaten by guards.

Federal prosecutors accused Corporal Bergen of covering up for fellow correction officers, who beat Mr. Pizzuto because he had clamored for his methadone treatment. Mr. Pizzuto, who was serving a 90-day sentence for traffic violations, died of a ruptured spleen a few days later.

Two officers, Edward Velazquez and Patrick Regnier, pleaded guilty this month to the fatal beating; a third guard, Ivano Bavaro, admitted to acting as a lookout and agreed to testify for the prosecution.